According to Variety, no frontrunner has emerged. But Gilroy, who wrote the previous Bourne films — The Bourne Identity, The Bourne Supremacy and The Bourne Ultimatum, which grossed nearly $1 billion combined worldwide — and wrote and directed Michael Clayton, wants to screen-test all contenders, which could give lesser-known candidates a leg up while creating a hurdle for more established actors.

Gilroy reportedly wants to move quickly on casting, as production is set to begin in the spring for an announced Aug. 3, 2012, release.